The California ISO has posted its 2023 Summer Loads and Resources Assessment on its website.

The assessment is available on the Reports and bulletins webpage, under the Seasonal assessments heading.

The 2023 Summer Assessment is an assessment of the expected 2023 summer supply and demand conditions for the California Independent System Operator (ISO) balancing authority area (BAA). The ISO publishes and shares with results of the Summer Assessment each year with State regulatory agencies, industry participants, and stakeholders. This 2023 Summer Assessment fits into a broader collaborative effort on behalf of the ISO, California Public Utilities Commission (CPUC), and California Energy Commission (CEC) to prepare for summer system operations and maintain grid reliability.

The 2023 Summer Assessment indicates considerable improvement in resource availability for the upcoming summer, compared to recent summers, driven by accelerated resource development and high hydro conditions.

• The ISO’s assessment of resource development demonstrates sound progress towards meeting the conventional “one day every 10 years” (1-in-10) Loss of Load Expectation (LOLE) planning target;
• Under current high hydro conditions, the resource fleet scheduled to be online by June 1, 2023 exceeds the 1-in-10 planning target with a margin of approximately 200 MW. Under average hydro conditions, there would be a shortfall of approximately 1,100 MW in meeting the planning target;
• Under current high hydro conditions, the resource fleet scheduled to be online by Sept. 1, 2023 exceeds the 1-in-10 planning target with a margin of approximately 2,300 MW. Under average hydro conditions, that margin would drop to approximately 960 MW;
• Although load has grown from 2022 to 2023, these results represent a significant improvement from the 2022 Summer Assessment, when there was a shortfall in reaching the 1-in-10 planning target;

These results do not take into account more extreme events such as those demonstrated in the last several years (e.g. extreme drought, wildfires and the continued potential for widespread regional heating events and other disruptions) that continue to pose a high risk of outages to the ISO grid.